Mortising gauge



Patented June 17, 1947 MORTiSING GAUGE Herbert Quigley, Grand Rapids, Mich, assignor to National Brass Company,

Grand Rapids,

Mich, a corporation of Michigan 7 Application October 21, 1944, Serial No. 5591815 This invention relates to a mortising gauge, particularly adapted and designed for mortising, at the edge of a door, a shallow rectangular recess in conjunction with a cylindrical opening bored into the door, said opening being provided for the insertion of the tubular housing of a lock or latch, and the rectangular recess in the edge of the door for receiving a similarly shaped plate of flat metal which is connected to the latch housing, the plate having openings for the passage of screws for securing the plate and the attached housing in secure relation to the door.

The present invention is directed to a very effective mortising gauge by means of which the material at the edge of the door is cut on lines which bound the rectangular mortise which is to be made. With my invention the cutting members of the gauge are separable so that each can be readily and conveniently sharpened, and they are releasably secured to the body of the gauge by means of a screw connection, utilizing a screw having a relatively large cylindrical head which in the use of the gauge is entered into the opening bored in the door for the reception of the latch tubular housing, thereby automatically properly positioning the gauge with reference to the door so that the boundary lines of the shallow rectangular mortise which is to be out are properly located.

An understanding of the invention may be had from the following description taken in connection with the accompanying drawing, in which,

Fig. 1 is a perspective View of the assembled mortising gauge made in accordance with my invention.

Fig. 2 is a fragmentary perspective view showing the edge portion of a door at which the mortising gaug is to be used, and

Fig. 3 shows perspective views of the disassembled parts of the gauge.

Like reference characters refer to like parts in the different figures of the drawing.

In Fig. 2 the door at I, at the free vertical edge thereof, at which a lock or latch is to be installed, is bored with a horizontal boring 2 inwardly into which the tubular housing of a latch or lock is to be inserted. The transverse opening 3 indicated is for the passag of the operating bar to which door handles or knobs are secured, said bar passing through th latch or lock housing, and said transverse opening 3 cutting across the housing opening 2. Such opening at 3 however is not concerned in any way with the present invention.

1 Claim. (01. 1 45-25) 2 In the construction of the mortising gauge which I- have devised, arelatively heavy body 4 of metal is enlarged at one end and formed into a rectangular section 5 having a flat outer face. opening 6 is made in said body extending from the flat fac of the section 5' into and in practice through the body of the gauge and, preferably, is reduced in diameter as indicated in dotted lines at 7 (Fig. 3), the portion i of'the opening being interiorly screw threaded. The cutting members of the gauge are two in number each made from flat steel stockinto channel form. In the one locatednext to the body of the gauge the web 8, of a substantially rectangular shape so as to seat against the flat face of the section 5 of the body 4, has an opening 9 therethrough for conjunction with the opening 6 in the body. Its flanges I0, one at each end of the web 8, are turned at right angles and are sharpened at their free edges as shown. The other cutting member of the gauge has a web H of a. length to be received within the flanges ID of the first described cutting member. An opening I2 is made through the web I l which in the assembly of the gauge is in conjunction with the opening 9 in the web 8. The flanges i 3 are at the sides of the web I I, being turned at right angles therefrom, and each at its free edge is also sharpened to a cutting edge as shown. The two cutting members are dimensioned so that the second one described may be nested against the first one with the webs B and II in contact engagement, whereby a frame of rectangular form is provided by the flanges l0 and I3, the cutting edges of all of th flanges being located in substantially the same plane.

A screw having a cylindrical head l4 and a threaded shank l 5 has the shank thereof passing through the opening l2, 9 and 6 and connected with the interiorly threaded opening at 1 in the assembly of the parts as shown in Fig. 1. The head M is relatively large and of cylindrical form, at its outer portion having an exterior diameter but slightly less than the interior diameter of the opening 2 bored in the door. In the use of the gauge the enlarged head i 4 of the screw is inserted at said opening l2 and the cutting edges of the flanges I0 and I3 brought against the edge of the door with the edges of flanges l3 substantially parallel to the sides of the door. By

use of a hammer or other equivalent tool the outer end of the body 4 may be struck against the cutting edges of the flanges l0 and I3 thereupon cutting into the material of the door, flanges l0 cutting on the lines indicated at l6 to be inserted in the opening at 2, such mortise cutting is expeditiously attained.

With the present mortise gauge it is apparent that the parts may be very quickly and easilydisassembled so that sharpening the cutting edges of the flanges Ill and I3 on the two cutting members may be easily and accurately accomplished, which could not be done if a single rectangular cutting member with flanges having cutting edges at both the sides and ends thereof was used. The enlarged head of the screw, dimensioned so as to be freely received in the opening l2, yet with a closeness of fit such that looseness of the screw head within the opening I2 is obviated, provides for a substantially instant proper location of the mortising tool with reference to the latch housing receiving opening at the outer end, of which the rectangular shallow mortise is to be cut.

This tool has proved very practical and useful. The invention is defined in the appended claim and is to. be considered comprehensive of all forms of structure coming within their scope.

I claim:

A mortising cutter comprising a body, two cutter members of channel form located one against the body and the other against the first cutter member, each of said cutter members having two flanges with sharpened edges, the flanges of one cutter member being located at right angles to the flanges of the other thereby providing a rectangular frame with sharpened outer edges located in substantially the same plane, and releasable means for securing said cutter members together and to said body, said releasable means having a head-extending outwardly beyond said flanges, the diameter of said head being slightly less than the diameter of the opening into which it is to be received in a body to be mortised around said opening.

HERBERT QUIGLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,629,053 Shrader May 17, 1927 1,118,570 Nedergaard Nov. 24, 1914 1,787,313 Houts Dec. 30, 1930 FOREIGN PATENTS Number Country Date 66,227 Sweden Oct. 23, 1928 

